There is a growing body of research focused on how angled fish respond to catch-and-release (C&R). However, most of those studies do not span a wide range of body sizes for the targeted species. Physical injury and physiological responses to C&R can be size-dependent, and methods used for landing fish of different sizes vary. As such, studying the response to C&R across a range of fish sizes may help inform best practices that improve outcomes for released fish. Northern Pike (Esox lucius) widely ranges in body size. Anglers may land them by hand, cradle, or net, and they are often released voluntarily or to comply with regulations. We angled 25 Northern Pike (total length 620–1030 mm) from one population and recorded fight, handling, and unhooking times across landing methods (i.e., hand, cradle, net). Prior to release, a pop-off biologging package was temporarily affixed to each fish to monitor locomotor activity, depth, and water temperature during a 12-h period post-release to understand how the interaction of landing method and body size influenced post-release behaviour and short-term fate. Fight and handling time increased with increasing body size. Northern Pike landed with a cradle or net had shorter fight times but longer handling times, compared to fish landed by hand. Post-release locomotor activity was greater for larger fish and those landed with a net. Fish <775mm and landed by hand had greater locomotor activity than fish landed with a net or cradle, while fish >775mm landed by hand had reduced locomotor activity compared to fish landed with a net. There was no post-release mortality observed. Collectively, anglers should use a net for Northern Pike >775 mm to avoid long fight times and reduce post-release exhaustion, but also attempt to reduce the extent of handling associated with fish landed by net.

Microfishing is an emerging form of predominantly catch‐and‐release recreational angling with the main target being diverse small‐bodied nongame fish species and the early life stages of traditional game fish. While there has been an apparent increase in interest in microfishing, little is known about its impacts on fish and fisheries. Here we compared the effects of two hook sizes (i.e., a size 22 hook and a somewhat larger, yet still smaller than normal, size 12 hook) on aspects of injury, handling, and mortality for juvenile Bluegill Lepomis macrochirus (size range of 69 to 141 mm; n = 54 for each hook size). Hook size was determined to have a significant influence upon injury and mortality. The smaller hooks resulted in longer handling time, more extensive tissue damage arising from challenges of hook removal, and higher levels of short‐term mortality (n = 12, 22%) than the larger hooks (n = 2, 4%). Additional research is needed to develop best practices and management strategies for this emerging form of recreational angling on a wider range of species.

We quantified effects of wind speed and sunlight on Smallmouth Bass (Micropterus dolomieu), a popular gamefish in North America, after catch-and-release (C&R) (n = 90) during August for various periods (0, 10, 30 and 90 s) in direct sunlight or shaded from direct sunlight. We evaluated change in skin temperature and reflex action mortality predictor (RAMP) scores. Changes in skin temperature were larger with increasing wind speeds and air exposure duration. Light intensity had no effect on skin temperature or RAMP. Generally, skin temperature decreased (i.e. colder) when wind speed exceeded ~5 km/h and increased (i.e. warmer) when wind speed was below ~5 km/h. Significantly, lower RAMP scores were associated with longer air exposure. Generally, Smallmouth Bass exposed to air for longer than 10 s were significantly more impaired prior to release. We recommend anglers reduce the time that large fish are exposed to air to reduce immediate reflex impairment.

Anglers typically use stringers to keep fish intended for harvest from spoiling or for high grading purposes (i.e., culling). However, relatively few studies have examined the effects of temporary stringer retention on the physical condition and post‐release mortality of fish. In this study, we examined blood physiology, reflex impairment, injury and 48‐hour fate of 168 Northern Pike Esox lucius after being exposed for 2 hours on one of five treatments: 1) cord stringer through the operculum, 2) cord stringer through the lower jaw, 3) metal stringer through the operculum, 4) metal stringer through the lower jaw, and 5) aerated tank control. Immediately after retention, blood lactate concentrations of stringer treatments were on average 42% greater relative to controls. Fish from the stringer treatments exhibited injuries of varying severity, most of which (e.g., gill lesions, expanded puncture wounds, swelling), were still present on surviving fish 48 hours later.. Reflexes were impaired for all stringer fish whereas control fish tended to have all reflexes intact. No fish died during the treatment period. The highest occurrence of mortality was within the first 8 hours following retention for the cord‐operculum (48%), metal‐jaw (15%), and metal‐operculum (19%) treatments. Stringers placed through the operculum had a higher mortality rate (37%) compared to stringers placed through the lower jaw (17%), regardless of stringer type. Overall, 27% of fish placed on stringers died and 68% of the remaining fish showed injuries related to stringers, while control fish showed low mortality (7%) and no meaningful injuries. Our results suggest that holding fish on stringers causes stress and injury levels that can result in post‐release mortality. As such, fisheries managers should consider restricting the release of fish placed on stringers, and once placed on a stringer, fish should be regarded as part of the daily harvest‐limit for a given angler.